Additive manufacturing (AM) is a serial material fabrication approach that implements an energy source, such as a laser or electron-beam, to melt, fuse, and sinter or cross-link a precursor material which can be delivered, e.g., in powder, droplet form or as a thin wire. In many of the current AM tools, the energy source or the stage holding the build (the article being built) is moved in a 2D pattern motion which defines the build-slice layer (base layer of the article being built). At the completion of the layer, more material is added and the build is lowered (as for example in the case where material is added in a powder-bed form) for the next build layer. Recent interest in, and development of, AM technology can at least partially be attributed to the development of very stable high power (200-400 W) fiber lasers that permit continuous layer-by-layer assembly that could last weeks for very large articles (e.g., articles having a volume on the order of 50×50×50 cm3). The first generation AM tools, for both polymer and metal, were intended as prototyping machines (e.g., for use in preparing prototypes for use in shape-form analysis). However, with recent advances in source material powder, rapid prototype tooling has evolved and is now poised to provide on-demand manufacturing.
For information regarding various exemplary implementations of AM, see the following references, the entire contents of each of which are incorporated by reference herein: Gu et al., “Laser additive manufacturing of metallic components: materials, processes, and mechanisms”, International Materials Review, 57(3): 133-164 (2012); Frazier, “Metal additive manufacturing: a review”, J. Mater. Eng. Perf. 23: 1917-1928 (2014); and Herderick, “Progress in additive manufacturing”, The Minerals, Metals & Materials Society (JOM), 67(3): 580-581 (2015).